Welcome to the new forum! We upgraded our forum software with a host of new boards, capabilities and features. It is also more secure. Jump in and join the conversation!
You can learn more about the upgrade and new features here.
For the equipment profile, your limitation is the size of your mash tun. So the definition of these in terms of weight, volume, and specific heat based upon the material is critical. The fact that you are doing partial mash is immaterial to the equipment profile and will be defined in your recipe by the recipe type. You can fill and drain your mash tun with a known amount of water to get some idea of how much dead space you have, do a 1 hour boil with an amount of water which will be close your pre-boil volume to obtain an initial boil off rate, and update the profile accordingly.